How to avoid fishtail in gluing and stitching process?
Carton forming has to go through a series of processes of printing, slotting, stitching or gluing, and strapping. With the improvement of equipment automation, these processes have evolved into one process. Each and every process in carton forming process will have an impact on the cost. In other words, the more processes that go through, the higher the cost. The larger the batch, the more automated the equipment, and the lower the production costs. However, in the case of more orders and less quantity per order, the cost in using single machine will be low and vice versa.Even with the high quality cardboard in the production of corrugator, if having a rough management in printing, slotting, scoring, gluing and other aspects, cannot up to the technical quality requirements, it will not produce qualified corrugated boxes.The impact of bad carton formation on efficiency Combined with national standards and user application practices, the general requirements for carton forming are:1).Slotting,angle cutting and scoring: The slotting and angle cutting is in right place, cutting to the center of the transverse scoring line, the cutting edge is ooth, neat, no crack damage, no burr, crease not cracked.2).Stitching (gluing) : The two edges of cardboard should be aligned. The seam is not deflected and the distance between the two ends is the same. Nailing along the middle line of the tongue, arranged neatly, uniform. Must nail firmly, re-nailing, nailing more or nailing less are not allowed.Poor carton formation has a great impact on the production efficiency of the carton factory, mainly reflected in:1) .Low production rate of qualified productsDefective production needs for personnel selection, it is a waste of labor costs.2).High production loss.Fishtail is irreparable, resulting in product waste.3).Increase in production complaintsScoring line is poor, how to use intelligent equipment to control?The main reasons of bad scoring line are: scoring line is too light; Vibration of scoring wheel or pre-scoing wheel; Scoring wheel design is unreasonable;Scoring line too light may be because:personnel operation is not correct; Gap display data difference of printing press; Scoring wheel wear.Causes of vibration of scoring wheel or pre-scoring wheel:●The pre-scoring wheel is not round;●The bearing of scoring wheel is run-out.●Cardboard transfer vibration;Scoring wheel design is not reasonable, may be because:●Scoring roller diameter is too all;●The design of bump point and R angle of scoring roller is unreasonable.Then how to improve the design of the scoring roller?●Design the scoring width and depth of scoring roller according to the company's products.●The arc of the pre-scoring wheel should not be too wide, and the R angle should not be too low.●The bearing of scoring line should not jump too much in high speed rotation.●The diameter of the scoring roller is enlarged;●The gap between the scoring wheel and the pre-scoring wheel should be corrected regularly.In the carton production process, the printing operators has insufficient self-knowledge about scoring, the standard is as long as the line is not cracked. As responsibility has to be taken, so simply reduce the scoring pressure. The second is improper adjustment of the scoring line, only to increase the pressure of the scoring wheel, not to adjust the pressure of the pre - pressure wheel, scoring cracks is easy to happen. Therefore, the operators are more reluctant to increase the scoring pressure, so the carton scoring line is not good.Scoring operating procedure: ●Scoring must be deep, reasonably adjustment should be done according to different materials and flute shape. The pressure of pre-scoring wheel should be increased to those cardboard with low moisture and grams, while secondary pre-scoring mode also should be used.●The scoring gap should be controlled in 1.8mm-2mm to double wall, and 1.2mm-1.5mm to single wall.2.How to use intelligent equipment to control askew paper feeding?Skew paper feeding refers to the paper tilted in the process of paper feeding. If having a skew feeding in paper feeding unit, it will cause printing ribbon in the wrong order, printing position skew, slotting dislocation, scoring line askew and fishtail etc.When the cardboard through the feeding wheel appeared askew, then it is doomed to the scoring line is oblique. Because the paper feed is tilted, it is impossible to repair through the printing unit and slotting unit, the scoring line can only be oblique. So after printing, not only to check the printing, be sure to check whether the cardboard is oblique. The slotting can be checked to see if the cut is on a corrugated line, if not, then it is oblique.In the production process of the printing press, the paper feeding skew is often encountered. The reasons are as follows:●Paper feed rubber roller wear seriously.After using for a period of time, the feeding rubber roller will be seriously worn, which will cause changes in the elasticity and pressure of the feed rubber roller. There is not enough friction to feed the paper.Tips: Usually to do a regular maintenance, if paper feed roller wear can not be used, to timely check and replace it.●Unqualified rubber feed roller was used.Feeding rubber roller belong to consumable parts, most of the original factory not covering warranty. Many customers, in order to saving costs, rather choosing the rubber roller of the unknown all factory instead the original ones after using the printing press for a period of time, or find a all factory to process the old roll. Because feed rubber roller is in the state of high-speed operation, in order to ensure the stability and uniformity of feed pressure, the rubber roller material, design hardness of original manufacturers have strict requirements. Large factories require wear resistance, temperature resistance, pressure resistance and other properties, while all factories and and their maintenance personnel know little about this.Tips: When buying equipment, we must choose qualified manufacturer product.●Improper operation, equipment operators improperly adjust the gap between the feeding rubber roller and bottom feeding roller.If the gap adjustment is too large, the contact between the cardboard and the feed rubber roller is not close enough, and the friction is all, resulting in unstable paper feeding and inconsistent position of paper feeding before and after feeding. If the feed rubber roller gap adjustment is too all, it will cause paper feeding difficulties, which can not be tranitted to the front of the printing unit. Generally these situations appear by those inexperienced operators. After they replaced the feed rubber roller, they do not correct the gap data between the feeding bottom roller and the feed rubber roller, resulting in the discrepancy between the actual gap and the size displayed by the computer. Therefore, the size of the rubber roller gap can not be quickly set correctly.Tips: Do a good training to new staff, improve operational skills.●The scoring line is too deepCardboard pressure adjustment is too large, resulting in cardboard indentation is too deep.Indentation is too deep, so that the thickness at the indentation of the cardboard is thin. When feeding, the pressure by indentation transferring to the feeding rubber roller is not enough, friction is reduced. This will cause the feed roller and cardboard slip, resulting in paper feeding position dislocated.Tips: Scoring line should not be too deep.●The feeding wheel of leading edge feed platform wear out or use poor quality tiresIf the feeding wheel of leading edge feed platform wear seriously, it will cause uneven feeding friction, resulting in the feed dislocated. Use inferior feeding wheel, because its material, hardness, size specification and original sun wheel have very big quality difference, it also affects the stability of the paper feeding .Tips:Timely check the feeding wheel of the leading paper feeding platform.●The air suction of paper feeding is not set properlyThe general equipment for paper feeding air suction can be adjusted. Now most of the use is frequency conversion motor, if the all and thin cardboard (the length is less than 650mm, the thickness is less than 3mm), then the air volume set to be aller. Air suction is too large, it will adsorb tightly, so that the cardboard against the screen caused pressure.Tips: For those all and thin cardboard, paper suction is to set up at a lower level.●The ventilation door of paper feeding suction is improperly setThe leading edge feed platform is provided with air door. In order to ensure uniform suction,the air door open of large and all cardboard should be different. Do not close the air door at both ends while producing large cardboard, otherwise resulting in paper feeding dislocation due to insufficient air suction.Tips: Do not close the air door at both sides when producing large cardboard.●Improper height adjustment of dust removal brushIn the production of thin cardboard, in order to ensure the effect of dust removal, the dust removal brush position is often lowered. When the production of cardboard, do not remember to adjust the brush position upward, resulting in collision between cardboard and brush, cardboard is meeting resistance, paper feeding is difficult, so the paper is dislocated.Tips: When producing the thick cardboard, remember to raise the brush to a higher position.3.How to intelligently control the instability of folding unit?The role of folding unit folder guler is to be able to gluing the carton and folding into formation through the gluing and folding mechani, and finally counting to stack. This process simplifies manual operation and improves production efficiency. Especially suitable for a large number of all and medium size carton production operations. Generally, the carton processed by the printing press is sending into the folding system, and then the gluing system which spraying glue liquid on the cutting edge of the carton, the carton will be gradually folded under the guidance of paper guide rod and paper folding belt during the conveying process, and the slot width and squareness of the joint will be controlled.Then by counting conveyor system, the carton will be stacked out according to the set sheet number.●Guide rodThe paper guide rod shall be adjusted according to the product position to ensure the normal entry of the first label into the folding unit.Paper guide rod vibration on the impact of gluing box: paper guide rod vibration affects the stability of paper transfer on the belt, affecting the carton formation.●Auxiliary guide rod: When the carton is formed, following the auxiliary guide rod to fold, and adjust the difference between the first and the fourth label according to the carton size.●Folding guide bar: The folding guide bar and the belt clamped to transfer the carton, and the seam size is related to of the folding guide bar adjustment.Belt correction speed difference detection and belt cleaning: the belt speed difference affects the carton gluing, if two belts produce speed difference, it will produce a fishtail.Belt used for too long, its surface becomes ooth, resulting in unstable paper tranission, and fishtail.Regarding the correction wheel, the following should be realized: ●Each wheel has a different clearance, which can be adjusted appropriately according to the product.●The correction wheel is made of rubber products and has the strength and elasticity when scoring.●Scoring wheel with paper guide rod for scoring correction.●The thickness of the paper rod and the angle is cooperative by the tape.●Correction wheel with guide rod to correct the carton seam.●The correction wheel is tapered.4.How to control product stack dislocation intelligently?When stacking carton products, pay attention to size adjustment and air suction control.●The difference between top stacking and bottom stackingFolding methodAdvantagesDisadvantagesTop stackingSimple structure and easy adjustment Easy to cause fishtail, no pressure on cardboard,so it is not easy to stack neatly. Bottom stacking Due to the pressure of the upper carton, the adhesion effect is good, easy to be alignment. The mechani is complex and synchronous adjustment is very important. ●The difference between big push plate and all push plateBig push plate is the a whole piece of push plate to pat the cardboard in alignment, all push board is divided into several pieces to pat the cardboard in alignment.Push plate stackingAdvantagesDisadvantagesBig push plateAdjustment is easy If the stress surface is not uniform, the effect is not ideal Small push plateIt can adjust the stress surface,which is conducive to patting; Pinion can be matched to prevent paper jamAdjustment is in complex ●Pressure wheel and pressure plateThe bottom stack is usually assisted by a pressure wheel or a pressing plate. In this way, the cardboard will not slip when stacking, and the paper feeding will be stable .If there is no plate, the paper is not stable, especially after oil or paper surface is particularly ooth, it is easy to slip.●Stacking width and belt gap of stacker platformThe width of the stacking should be noted. Width should be 1-3mm less than the width of the cardboard, so that the cardboard can be patted in a tightly manner. At the same time, pay attention to the belt gap. That is, the belt gap of the stacker platform, the belt gap is two-thirds of the width of the cardboard, only in this way, the cardboard below can be transferred.